Need help with an annoying issue. I have two channels that won't work on two of the four tvs I have connected. Spike HD 554 and Comedy Central HD 690. Already replaced splitters, about to replace cable. Want other tips before calling a tech to fix.

Make sure that all the coax connectors are good meaning that the connector is on the cable tightly and not loose, try pulling on the cable and check to see that all the connections are tight. Usually in a case like this, the signal is low or marginal. It may be that the optical connectors from the hub to your ONT need to be cleaned or maybe that the ONT is defective.